The contents of the 20-minute tape were discovered by a shocked member of the public after it was picked up at a sale in Euxton, near Chorley, with other tapes thought to be blank videos, for less than £1.

It reveals compelling air and ground footage of the medium security Ulnes Walton jail, near Leyland, under siege by inmates in 1993, and the methods police and prison officers used to bring the violent eight-hour dispute to an end.

The colour video was bought with a Lancashire Constabulary sticker carrying a request for it to be returned after use to the force’s Criminal Intelligence Unit.

The embarrassing blunder was rapped by former deputy chief constable of Greater Manchester police, John Stalker. He said: “It is very embarrassing for this video to find its way into the public arena. The system has to be tightened up.”

Lancashire police’s assistant chief constable John Vine, was considering a top level probe into how the video found its way into public hands.

The riot on September 6, 1993, left the Category C jail in ruins with a damage bill running to well over £20m.

About 400 of the 800 inmates were involved.

Cornershop crew storm the charts

Preston’s pop starlets are brimming over with success after storming the charts with their latest blockbuster.

Cornershop, formed in the town during 1992, have raced to the number one slot in the official charts with the single Brimful of Asha.

And to celebrate their achievement the band are heading back into town to play for their army of local fans.

The band was formed by University of Central Lancashire students Tjinder and Avtar Singh, Dave Chambers and David Ayres.

Cornershop outsold a host of famous artists to become top of the pops, including Celine Dion, All Saints and Aqua.

The single was originally put together at the West Orange recording studios in Ashton, Preston.

Trending

In pictures: Chapter one of Burnley children celebrating World Book Day in style

Luxury hotel appearing on Burnley skyline

The average wage paid by Burnley and their Premier League rivals - ranked in order

More exciting images from the new Crow Wood Hotel in Burnley

Drunk woman arrested in her nightclothes for being drunk and disorderly near Turf Moor